280 S. WELLER FAUNA OF THE FERN GLEN FORMATION 



Burlington faunas, but in the absence of the arm characters it is not safe 

 to identify it with any of them, nor to describe it as new. 



CCELIOGRINUS sp. 

 Plate 11, figure 27 



This species is represented by the terminal portion of the ventral sack 

 only, several specimens of which have been examined. Several species of 

 the genus are known from the Lower Burlington limestone, but with the 

 incomplete material available it is not possible to identify the Fern Glen 

 specimens with either of them. It is possible that two species are repre- 

 sented among the Fern Glen specimens. 



GRAPEIOCRINUS SAMPSONI n. sp. 



Plate 11, figure 23 



Description. — Calyx much depressed and very shallow, the stem facet 

 situated in a deeply excavated depression. Underbasal plates small, com- 

 pletely covered by the column, not distinguishable in the type specimen. 

 Basals longer than wide, pentagonal except the posterior one, their great- 

 est width below the middle, just outside the margin of the excavation for 

 the column, where their proximal portions are abruptly bent inward in a 

 nearly vertical direction; distally the lateral boundaries of the plates are 

 not straight, but contract more rapidly toward their extremities ; posterior 

 basal larger than the others, its distal extremity broadly truncated. 

 Badial plates very thick, much wider than high, nearly horizontal in 

 position, their articular faces nearly as large as the external surface, 

 articular ridges well developed. Anal plate rather large, resting on the 

 truncate posterior basal between the two postero-lateral radials, its distal 

 extremity extending slightly above the articular surfaces of the radials. 

 Badianal plate absent. External surface of the plates, except in the 

 depression for the column, marked by scattered, low, but rather coarse 

 tubercles. Arms and ventral surface unknown. 



The dimensions of the type specimen are: Width, 12 millimeters; 

 height of dorsal cup, 4.5 millimeters. 



Remarks. — This species may be distinguished from other members of 

 the genus by its much depressed calyx and the tubercular ornamentation 

 of the plates. It is not closely related to any other species. The species 

 has been named in honor of Mr F. A. Sampson, who has been the most 

 successful collector of crinoids in the Fern Glen fauna. 



